Ed Voas on the story behind Tweetsville, the clever new $4 Twitter client he wrote (but which he sold to Tapulous, because he’s going back to work for Apple):

For the next few weeks I worked pretty much 24/7 getting things to cache properly, push things off onto threads as much as possible, use a real database, etc. and make sure that things just worked correctly. Despite the simplicity of what Twitter is, making an application to really behave properly and ensure that things are always as you expect is pretty darn hard. Even something as ’simple’ as clicking a tweet and then iterating your tweets with the up and down arrows in the upper right was interesting. Not because of the iteration of the items, but because you now have yet another view that needs to be aware of state changes in the application. For example, if you favorite something, I needed to make sure that if it was showing elsewhere in the UI the change was reflected. Good times.